diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 6fa6d2d..aecca8e 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -15,7 +15,7 @@ jobs:
   pytest:
     strategy:
       matrix:
-        python-version: ["3.10.15", "3.11"]  # Omit until shutdown fixed: , "3.12", "3.13"]
+        python-version: ["3.10.15", "3.11", "3.12", "3.13"]
         os:
           - "ubuntu-latest"
           - "windows-latest"
diff --git a/src/ezmsg/util/messagereplay.py b/src/ezmsg/util/messagereplay.py
index 9ab4b57..6efc71a 100644
--- a/src/ezmsg/util/messagereplay.py
+++ b/src/ezmsg/util/messagereplay.py
@@ -31,7 +31,7 @@ class ReplayStatusMessage:
     done: bool = False
 
 
-@dataclass
+@dataclass(frozen=True)
 class FileReplayMessage:
     """
     Add a file to the queue.
diff --git a/tests/test_messagereplay.py b/tests/test_messagereplay.py
new file mode 100644
index 0000000..64b57a9
--- /dev/null
+++ b/tests/test_messagereplay.py
@@ -0,0 +1,92 @@
+"""Tests for ezmsg.util.messagereplay module."""
+
+import json
+import typing
+from dataclasses import fields
+from pathlib import Path
+
+import pytest
+
+import ezmsg.core as ez
+from ezmsg.util.messagecodec import MessageEncoder, LogStart
+
+
+def test_import():
+    """Importing the module should not raise (regression: frozen dataclass inheritance on 3.13+)."""
+    from ezmsg.util.messagereplay import (
+        FileReplayMessage,
+        MessageCollector,
+        MessageReplay,
+        MessageReplaySettings,
+        ReplayStatusMessage,
+    )
+
+
+def test_replay_status_message():
+    from ezmsg.util.messagereplay import ReplayStatusMessage
+
+    msg = ReplayStatusMessage(filename=Path("/tmp/test.log"), idx=3, total=10)
+    assert msg.filename == Path("/tmp/test.log")
+    assert msg.idx == 3
+    assert msg.total == 10
+    assert msg.done is False
+
+    msg_done = ReplayStatusMessage(filename=Path("/tmp/test.log"), idx=10, total=10, done=True)
+    assert msg_done.done is True
+
+
+def test_file_replay_message_defaults():
+    from ezmsg.util.messagereplay import FileReplayMessage
+
+    msg = FileReplayMessage()
+    assert msg.filename is None
+    assert msg.rate is None
+
+    msg2 = FileReplayMessage(filename=Path("/tmp/test.log"), rate=10.0)
+    assert msg2.filename == Path("/tmp/test.log")
+    assert msg2.rate == 10.0
+
+
+def test_message_replay_settings():
+    """Settings should inherit from both ez.Settings and FileReplayMessage without error."""
+    from ezmsg.util.messagereplay import MessageReplaySettings
+
+    settings = MessageReplaySettings()
+    assert settings.filename is None
+    assert settings.rate is None
+    assert settings.progress is False
+
+    settings2 = MessageReplaySettings(filename=Path("/tmp/test.log"), rate=5.0, progress=True)
+    assert settings2.filename == Path("/tmp/test.log")
+    assert settings2.rate == 5.0
+    assert settings2.progress is True
+
+
+def test_message_replay_settings_is_frozen():
+    """ez.Settings subclasses should be frozen dataclasses."""
+    from ezmsg.util.messagereplay import MessageReplaySettings
+
+    settings = MessageReplaySettings()
+    with pytest.raises(AttributeError):
+        settings.progress = True
+
+
+def test_message_replay_unit_streams():
+    """MessageReplay unit should have the expected stream attributes."""
+    from ezmsg.util.messagereplay import MessageReplay
+
+    assert hasattr(MessageReplay, "INPUT_FILE")
+    assert hasattr(MessageReplay, "INPUT_PAUSED")
+    assert hasattr(MessageReplay, "INPUT_STOP")
+    assert hasattr(MessageReplay, "OUTPUT_MESSAGE")
+    assert hasattr(MessageReplay, "OUTPUT_TOTAL")
+    assert hasattr(MessageReplay, "OUTPUT_REPLAY_STATUS")
+
+
+def test_message_collector_collects(tmp_path):
+    """MessageCollector should be instantiable and have an empty messages list."""
+    from ezmsg.util.messagereplay import MessageCollector
+
+    collector = MessageCollector()
+    assert hasattr(collector, "INPUT_MESSAGE")
+    assert hasattr(collector, "OUTPUT_MESSAGE")